One difference between the california and federal executive branch is that .
a) only the president has the line item veto on budget bills
b) there are more state elected officials
c) only the president has term limits
d) only the president nominates his cabinet

D) Only the President nominates his cabinet                  

Explanation:

The chief executive in the State of California and in the Unites States are quite similar but the only difference lies in the other part of the executive branch. In California government, all the other members of the cabinet including the Lieutenant Governor, the Controller, the Attorney General, the Secretary of State and others are directly elected by the people through voting.

Whereas, in the Federal government, all the parallel function are nominated by the President of the United States. In other words, President of the United States of America nominates his own cabinet.

Hence the correct option is -- (D).

c. wright mills's sociological imagination suggest investigating to explain this increase?